GENERAL INFORMATION ON SEALED LEAD-ACID BATTERIES
1.1 General Features
The LCR-Battery is a new type of sealed lead-acid
rechargeable battery system developed by Matsushita
Battery Industrial Co., Ltd. The lead-calcium rechargeable (LCR) battery, will stand up to tough operating condition such as overcharge and deep discharge. In field
service, troubles due to abnormal, improper operation
or misuse are reduced to a minimum. This section highlights the major features of the LCR battery.
1.1.1 High Quality & High Reliability
The LCR battery has stable and reliable capacity. It
can be easily maintained to permit proper operation of
the equipment that it powers. The battery withstands
overcharge, overdischarge, vibration and shock, more
readily than competitive products, and is capable of
extended storage. To assure this high quality and reliability, LCR batteries are 100% tested on line for voltage, capacity, and seals. And all vents are 100% visually inspected during the final assembly process.
1.1.2 High Power Density
Through accumulated experience in high technology
products such as VTR’s, computers, and electronic
equipment, Panasonic has acquired the knowledge
needed for developing and manufacturing batteries with
high power density. These batteries save installation
space, while providing full and reliable power for the
equipment, and many have been designed for rapid
recharge, or for high power output. As a result, this
power is used for applications ranging from VTR’s to
vacuums, electric tools, engine-start UPS systems and
computers.
1.1.3 Quick Chargeability
Where rapid recharge is required for portable devices
such as tools, computers or medical equipment, high
charge rate batteries (designated LCS) are available.
Coupled with the proper charger, recharge in 1-1.5
hours is readily achieved.
1.2 Features of LCR Battery
1.2.1 Leakproof design
The LCR battery uses an absorbed electrolyte system.
All of the eletrolyte is absorbed into the positive plates,
negative plates, and the separator material. Coupled
with the use of special sealing epoxies, tongue and
groove case and cover construction, and long-sealing
paths for posts and connectors, the LCR batteries have
exceptional leak resistance, and can be used in any
position. (The LCL & LCS batteries can be discharge in
any position but should not be charged while upside
down.)
1.2.2 Long service life in float or cyclic
The LCR battery has long life in float or cyclic service.
The life expectancy is shown on page 10.
1.2.3 Maintenance-free operation
There is no need to check the specific gravityu of the
electrolyte or to add water during the service life. The
LCR battery is totally sealed, and needs only charging
for maintenance.
1.2.4 No corrosive gas generation
There is no corrosive gas generation during normal use.
1.2.5 Exceptional deep discharge recovery
LCR batteries have exceptional deep discharge recovery and charge acceptance, even after deep or prolonged discharge, as illustrated in Figure 1.
Figure 1
Rechargeability after a Long Time Standing
in Overdischarged State
1.2.6 DOT & IATA approval
The LCR batteries are considered as safe as dry cells,
and have been approved for shipment by air by both
DOT and IATA
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1.2.7 U.L. Component Recognition
U.L. Component Recognition under U.L. 924, Section
38, for Emergency Lights and Power Supplier (not UPS),
requires that the battery safely vent when overcharged,
and tested under mineral oil. It further requires that the
equipment and battery be submitted together for formal U.L. approval. (U.L. Component Recognition does
NOT remove this requirement for complete pack-age
testing). Many Panasonic batteries have already passed
this vent test are used extensively in emergency lighting and related applications.
(File. MH13723...LCR6VI.2P, LCR6V3P, LCR6V3.2P,
LCR6V4P, LCR6V6.5P, LCR6V8P, LCR6V10P,
LCR12V1.9P, LCR12V6.5P, LCR12V17P, LCR12V24P,
LCL12V20P, LCL12V24P, LCL12V38P, LCS386,
LCS414P, LCS2012APC)
For assistance with U.!... requirements for your specific
appication, please contact Panasonic headquarters.
Lights, fire and burglar alarms, communication
systems, fire shutters.
Memory Back up
UPS systems, electronic cash registers,
computers, sequencers.
1.4 Construction
1.2.8 Vds Approval
LCR12V6.5P, Vds-No.: G184030, LCR12V3PF Vds-No.:
G186070, LCR12V1.9P Vds-No.: G185045, LCR6V3P
Vds-No.: G186048, LCR12V24P Vds-No.: G185046
LCR12V10PF Vds-No.: 187041
LCR6V10 Vds-No.: 187040
1.4.1 Positive Plates
Positive plates are made from a Lead–Calcium system.
1.3 Applications
1.4.2 Negative Plates
Negative plates are made from a Lead-Calcium system.
1.3.1 For Cyclic Use
Consumer Applications
Portable VTR/VCR,TV, record players, tape recorders, vacuum cleaners and appliances, and as portable power supplies.
Communication and Telephone Equipment
Cordless portable telephones, and transceivers.
Office Equipment
Portable calculators, computers, electronic
cashregisters, printers, and typewriters.
Tools and Engine-start
Grass and hedge trimmers cordless drills, screw
drivers, engine-start, and electric saws.
Instrument and Medical Equipent
Electronic instruments, measuring equipment,
medical electronics, and heart defibrillators.
Photography
Electronic cameras strobe, VTR and moie lights
Toys and Hobby
Radio-controllers, motor driving, lights.
1.3.2 For Trickle or Float Charge Use
Emergency Devices
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1.4.3 Separators
The glass fiber separators in LCR batteries have high
resistance to acid, and low electro-conductivity.
The high porosity of the separators retains adequate
electrolyte for the reaction of active materrials in the
plates.
1.4.4 Safety Vents
The venting system, which operates at 1 psi to 6 psiis
designed to release excess gas and keep the internal
pressure within the optimum range of safety, while it
protects the negative plates from contamination from
oxygen in the air Vents are 100% visually inspected
during production
1.4.5 Terminals
Depending on the battery model, the terminals may be
Amp Faston Type 187,250 or bolt and nut. Excellent
terminal sealing construction has been achieved by using long mechanical sealing paths and the selection of
small shrinkage ratios for the sealing materials. Please
see page 22 section 2.6.
1.4.6 Case Materials
Unless otherwise specified, (some larger sizes may use
polypropylene.) the case and cover are manufactured
from ABS or PP resin.
The above gas generation and absorbing reactions can
be expressed as follows.
1.5 Electrochemical
Processes
(A) The electrochemical processes of sealed lead acid
batteries are described below.
In this process, charging and discharging are reversed
with high efficiency, with the electrical energy used
during discharge being regained during recharge.
(B) In the final stage of charging, an oxygen – gas
generation occurs at the positive electrode :
This oxygen converts to the open surface of the negative, after which an absorbing reaction occurs at the
negative and absorption takes place.
Because the oxygen gas generated in the final stage of
charging is absorbed by the negative, as shown by
equations(1) and (2) , there is no increase in internal
pressure, despite the seald construction. When, however, the charging current exceeds the specified value,
or when charging is conducted at less than the specified temperature, the amount of gas generated by reaction (1) cannot all be absorbed by reaction (2). In
that event, an increase in internal pressure develops,
and, in the worst case, the safety vent is activated.
The gases released from the safety vent include Hydrogen, which is generated at the negative plate (along
with oxygen) during the electrolysis that takes place
during excessive overcharge.
(C) It should be noted that when the safety vent functions, electrolyte is consumed and performance deteriorates. To prevent or reduce this, it is important that
charging should be conducted under recommended
conditions.
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1.6 General Characteristics
1.6.1 Charging
Charging method:
The batteries should be charged using a method selected from table 1. (A detailed discussion of charging can be
found in section 1.7)
Table 1 Charging method & battery application
Application
I
II
Cyclic operation
Trickle operation
Charging method
Constant voltage
Regulation range of
controlled voltage:
6 volt batteries:
7.3V to 7.5V
12 volt batteries:
14.6 V to 15.0 OV
Initial current:
0.4C or less.
Short-time charge
allowed.
Constant current
Charging current:
Approx: 0.1 C.
Charging time
control is recommended because
an overcharge is
more likely to occur.
Combination
(Note: all at 77๐F, 25๐C)
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Regulation range of
controlled voltage: 6
volt batteries:
6.8V to 6.9V
12 volt batteries:
13.6V to 13.8V
Initial current: 0.4C
or less. This method
can provide a
short-time charge.
Voltage must be
regulated or battery
may be overcharged
or overdischarged
Not applicable.
III
Float operation
IV
Refresh charge
during storage
Regulation range of
controlled voltage:
6 volt batteries:
6.8V to 6.9V
12 volt batteries:
13.6V to 13.8V
Initial current:0.4C
or less. Not allowed
to use if current
capacity of the
charger is not big
enough to main tain
the specified
charging voltage
during float.
Regulation range of
controlled voltage: 6
volt batteries:
7.5V to 7.5V
12 volt batteries:
14.6V to 15.0V Initial
current : 0.4 C
or less. Short-time
charge allowed.
Several of the same
model batteries,
under the same
storage, con be
charged in series.
Otherwise they
should be recharged
in separate groups.
Not applicable.
Charging current:
Approx. 0.1C.
Charging time control
Is recommended
because an overcharge is more likely
to occur
Two-step charge:
Charging current:
Approx. 0.4C at the
first step. 0.002C
To 0.005C at the
Second step.
A time control or a
Charging voltage
detection device is
required to transfer
from the first step to
the second.
Please contact Panasonic for further information.
Note : C rates in the table refer to current as a percentage of rated capacity
Example : for model LCR 6V3.2(3.2Ah)
0.4C = 0.4X3.2 = 1.28 amps.
1.6.1.1 Charging-Temperature Compensation
It is recommended that the charge voltage be adjusted
to compensate for the battery temperature as shown
below. If desired, this may be done by detecting the
ambient temperature nsar the battery instead of the
battery temperature. (also see Section 1.7.5.1)
Tch: time required for charge (hours)
Cdis: ampere-hour discharged before charge started
I: Initial current
Complete charge time for trickle service will be slightly
more than 24 hours.
1.6.1.4 Charging Temperature
1. The battery should be charged at an ambient tem
perature within the range of 32 to 104 F (0 to 40 C)
2. The most effective charging temperature range is
41 to 95 F (5 to 35 C).
3. Charging at temperatures below 32 F (0 C) or over
104 F (40 C) is not recommended; the battery might
be deformed by heat, or not charged enough.
4. See section 1.6.1.4 for temperature compensation.
1.6.1.2 Constant Voltage Charger-Characteristics
The graph below shows the output V-I characteristics
of the recommended charger
1.6.1.5 Reverse Charging
Do not chare in reverse. Reverse charging will damage the battery or charger circuitry.
1.6.1.6 Overcharging
Any extra charge after the battery is fully charged, is
called overcharge. Continued overcharge shortens the
battery life. Select the charge particularly specified or
approved for each application.
1.6.1.7 Charge before Use
It is recommended that batteries should be charged
before use to compensate for normal capacity loss during storage. See table 1 column IV, page 7; or section
1.7, page 11-16.
V (preset voltage) : an output voltage that is preset at
current
(Voltage stability) : the larger this absolute value, the
longer the charging time becomes, even with the same
preset voitage.
1.6.1.3 End of Charge
The time required to complete each charge depends
on the discharged condition of battery, characteristics
of charger used, or the temperature during charge.
This time can be estimated by the following expression
for cyclic use:
1.6.2 Discharging
1.6.2.1 Battery Selection
1. Select operating current.
2. Select operating run time.
3. Determine the closest amp-hour capacity to meet
reauirement. (Amper-Hour Selection Chart, page 21).
4. Use the battery Index on page 19~20 to select the
closest battery votage, size and weight to meet
application requirements.
5. Example: 2.9 Amps, 1.5 hours
12 volts
Space: 100mm x 160 mm x 105mm
Selection: 6.5AH
LCR 12V6.5(94mmx151mmx100mm)
6. Detailed curves and dimensions can be found for
each individuai battery, on data sheets in Section 3.
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1.6.2.2 Discharge current rates and recommended cutoff voltage
Figure 5 gives recommended cut-off voltages for 6V or
12V batteries, consistent with discharge rates [Note; In
some applications, a specific cutoff voltage may be required by local or national codes. For example, emergency lighting normally requires a cutoff of 1.75V cell
on a lead-acid battery (5.25V or 10.5V)]
1.6.2.5 Discharge current
For best efficiency, discharge within the range of 0.05
C to 2C Higher rates are allowed as published. For special assistance, contact Panasonic.
1.6.2.6 Deep discharge
Although Panasonic LCR batteries have unusually excellent deep discharge recovery capability, if the batteries are repeatedly discharged below specified cutoff
voltage, battery life is shortened.
1.6.3 Storage
1.6.3.1 General storage conditions
The battery should be stored under the following conditions.
1. Low humidity
2. 5 to 104 F (-15 to 40 C)
3. Clean, and out of direct sunlight
1.6.2.3 Discharge temperature
1. The ambient temperature during discharge should
be held within the range of 5 to 122 F (-15 to 50 C).
2. Low temperature (below 5 F – 15 C) may reduce the
available capacity; and high temperature (over 122 F,
50 C) may bring about thermal run-away and damage
the battery.
1.6.2.4 Effect of temperature upon performance
The available capacity is affected by both temperature
and discharge current as shown in Figure 6.
1.6.3.2 Capacity after long term storage
After long term storage, all batteries deliver less than
rated capacity on first cycle. In cyclic application full
capacity will be obtained through several charge discharge cycles.
In float application, full capacity will be achieved with in
24-48 hours, when charged at 2.3V/cell.
1.6.3.3 Refresh charge
When batteries are in extended storage, it is recommended that they receive a refresh charge at recommended intervals;
1.6.3.4 “Shelf Life” – capacity vs time
Self-discharge rate is very much dependent on the storage temperature as shown in Figure 7. Lower temperatures allow the battery to be stored for longer periods.
(Each ten degree centigrade drop results in a halfing of
self-discharge rate and doubles sorage time.)
1.6.3.5 “Shelf Life” – Storage time vs temperature
Figure 8 shows the time for the capacity to decrease to
50% of nominal capacity at each temperature during
storage. If the storage temperature is known, the graph
may be used for finding the most useful recharge intervals.
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1.6.4 Temperature Range Summary
Discharge :
Charge :
Storage :
5๐~122๐F
32๐~104๐F
5๐~104๐F
-15๐~50๐C
0๐~40๐C
-15๐~40๐C
1.6.5 Battery Life
1.6.5.1 Cyclic life
Cyclic life is very much dependent on the depth of
descharge that the battery encounters during each
cycle. This is shown in Figure 10.
1.6.3.6 Open circuit voltage & Residual capacity
Residual capacity can be estimated by measuring the
open circuit voltage as shown in Figure 9.
1.6.5.2 Float or Back up Life
The expected float life at room temperature is approximately 8 years on the basis of accelerated tests. This is
shown in Figure 11, based on tempera ture compensate valtage, per Figure 3.
Using too high or too low float voltage will shorten battery life, through overcharge or undercharge
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1.7 Charging Methods
In brief, charging is the process of supplying direct
current to the battery so as to convert it back into a
chemical state at high energy level, capable of delivering electric power. There are a variety of charging methods which can be used to charge sealed lead-acid
batteries. From the view point of controlling the charging process, these methods can be classified in to some
basic categories constant-voltage, contant-current, tapered-current and combination charge systems. (There
are some other special methods used to control the
charge by detecting internal pressure or battery temperature.) The above types (with the exception of the
special methods) are discussed here: (a summary chart
appears in section 1.6.1)
1.7.1 Constant Current Charging
Constant current charging is one of the most well known
methods. The advantage of constant current charging
is the ease of determining the amount of capacity (amp
hrs) supplied during charging; and there is no need for
temperature compensation which is required in constant voltage systems. On the other hand, the required
charging time should be strictly adhered to, especially
at high currents which provides a full charge in a short
period. On high-rate charge, the battery voltagerises
excessively and the water decomposes, accompanying heat generation at the final stage of charge. This
can damage a battery. The constant current method
however, may be satisfactory when the charge rate can
be kept at a relatively low rate and charging time is not
critical. Because of self-discharge, batteries reguire a
refreshing charge from time to time during storage. A
constant current charge may be used as a refreshing
charge when many batteries are charged at one time,
as this method will easily determine the amount of
charge returned to the battery. Batteries, which have
been left on the shelf under the same known condition,
shall be recharged approximately 120 percent of the lost
capacity (Ah), as estimated from the data shown in fig 7.
If storage conditions such as temperature and time are
known, but different for each battery, the charging
amount shall be based on the worst storage condition
or the largest lost capacity. For longest life, it is not
recommended to repeatedly use constant current
charging for refreshing the batteries. It is also important to minimize the need to repeat the refreshing
charge, by always keeping the batteries under a wellcontrolled stock rotation plan. Storing at lower
emperature is the key to battery shelf life. If stored at
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a high temperature, batteries will require frequent refreshing charges.
1.7.2 Constant Voltage Charging
It is very often necessary to restore batteries to a fully
charged condition in as short a time period as practical. In doing this, much care must be exercised not to
exceed specified charge rates or charge voltages as
the battery is approaching a fully charged condition. A
constant voltage charger can accomplish this type of
charging. Ideally such a charger should have very
stable output voltage and high current capacity, as extremely large currents are allowed to flow at the initial
stage of charge, where the battery voltage is low. This
type of charger, however, is not practical because the
requirement of a high current capacity or a negligible
small impedance for the power transformer, results in
high cost and a large and heavy charger. Undesirable
heat generation inside the battery cells, caused by initial high current, should also be taken into consideration. In general, a commonly utillized constant voltage charger has a device to limit initial current. This
current limitation can be accomplished by a constantcurrent regulator, a properly designed output voltage
from the power transformer, or by designing the overall
impedance of the circuit (for example by using a current regulating resistor). A constant voltage charger
will perform effectively for charging in a short time, as
during the final stage of charge the current automatically decreases, and the water decomposition will be
minimized.
1.7.3 Tapered Current Charging
This is a simple and relatively inexpensive method. The
circuit requires a power transformer, rectifiers and a
suitable resistance for limiting current. In this system,
the charging current drops gradually as the charging
proceeds. If the impedance of the circuit is low, a step
current slope can be obtained. This type for charge is
generally considered to be unsuitable for charging
sealed lead-acid batteries because the charging current will vary with fluctuation of line voltage as well as
changes in battery voltage. These effects, however,
can be minimized by using a power transformer with a
secondary voltage which is considerably higher than
the battery votage and a suitably high resistance in the
circuit for current limiting. This type of charger will perform similar to a constant current charger, and can be
utilized instead of a constant current charger for industrial uses; not only for recharging many batteries at one
time, but also as a tricke charging system.
1.7.4 Combination Charging (Two-step)
A combination charging employs two types of charging. It’s called a “Two-rate” or “Two-step” charging. A
variety of couples can be made, such as constant –
current/constant current, constant-voltage/constant-current and so on. In general the first step uses a quick or
fast charge mode, and the second uses a low charge
current. The switching from the first step to the second
can be carried out by many different methods; battery
voltage sensing, a time control, charge current sensing
etc. Some of these typical charging patterns are shown
in Figure 12.
specified level at the final stage of charge, and to suppress the initial current below the designated maximum
value as follows;
Constant Voltage Charge:
Initial current: 0.4 C* or less
Regulated voltage: 7.3 to 7.5V/per 6V battery
(Note)
* C means the nominal capacity.
The regulated voltages are at a tem
perature of 68๐ F (20๐ C)
For a 12V – or a 24V-battery, the regulated voltage
(above) shall be multiplied by 2 or respectively. If the
battery will be charged in a wide range of ambients, it
1.7.5 Charging Application Notes
All of the charging methods discussed above are commonly used with satisfactory results. Applications of
sealed lead-acid batteries can be classified roughly into
two types; cyclic operation and standby service and
must be charged accordingly.
is desirable for the charger to be temperature-compensated as shown in Figure 13.
1.7.5.1 Cyclic Operation
Cyclic applications generally require a short time charge
and protection against excessive charges and discharges, because the battery may be operated under
unfavorable conditions by inexperienced users. The
most important requirements in a constant voltage
charge technique are to hold the output voltage at the
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Without temperature compensation, the charge might
be excessive in a high ambient area, insufficient in a
low ambient area, resulting in cycle life patterns as illustrated in Figure 14.
1.7.5.2 Standby/Backup Charging
LCR batteries (unless otherwise noted) can be utilized
in standby applications, where they normally are kept
in fully charged condition, and serve as a power supply
to the load only when AC power fails. There are two
modes of charging standby applications; trickle-and
float charge.
1.7.5.2.(a) Trickle Charge
This is a system in which AC power is normally supplied or operating the equipment, while charging the
batteries which are not connected to the load. If AC
power fails, a relay circuit connects the batteries to the
load and battery power is supplied. Trickle charging is
generally considered to compensate for self discharge
by continuously charging the battery at a low constant
current to keep it fully charged. A constant voltage
charge can accomplish this objective. The appropriate
current rate for trickle charge is
0.002C to 0.005C. (C/500 to C/200)
In applications where AC power failure occurs infrequently, and the discharge is very small, the battery will
be restored to a fully charger condition in short time,
even at such a low current rate. In the case of deep
discharges, this method will take an extremely long time
to charge the battery. A two-rate charger, or a constant
voltage charger, is recommend for solving the problem, because of their initial quick charge modes. A two
rate charger has a distinct advantage, as there is no
need for temperature compensation.
A constant voltage charger requires some precautions
as follows:
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(1) In these applications, the batteries are subjected
to constant charging so long as a voltage differ
ence exists between the battery and charger volt
ages. The charger voltage, therefore, must be sta
bilized in a narrow range during trickle charge.
(2) When using the battery in a wide range of ambi
ents, the charger should be temperature compen
sated, as the charge characteristics will be greatly
affected by the ambient temperature. (See Figure
13.)
Typical data for trickle charge application is shown in
Figure 15.
1.7.5.2.(b) Float Charge
This is a system in which the load and the battery are
connected in parallel with the rectified power source.
This system requires only a constant voltage charger,
in which the charge voltage is stabilized in a range of
6.8V to 6.9V per 6V battery, regardless of the power
consumption by the load. As the regulated voltage of a
float charger is very close to the open circuit voltage of
the battery, major fluctuations in the charge voltage may
cause many small discharges of the battery while on
float. In other words, the constant voltage charger
should be designed for the maximum load or the maximum load should be balanced within the stabilizing ability of the charger. Otherwise the life of the battery can
not properly be estimated due to the irregular and complicated discharge patterns. In general, life in folat service may be some what shorter than in trickle charge
service.
1.7.5.3 Charger Design
1.7.5.3.(a) General Considerations
Battery life is affected not only by performance of the
charger, but also by operating conditions. Charger,
selection and design, therefore, must consider battery
usage as well as charging characteristics. All charger
designs use the same fundamental principles and require knowledge of the following basic parameters.
(1) the internal resistance of the batteries
(2) the initial and final charge current and or voltage
value,
(3) the charges in battery voltage during the charging
process,
(4) the required charging time,
(5) the effect of variable conditions such as ambient
temperature and changes in voltage on the battery
parameters,
(6) the maximum overall cost for the charger and bat
teries, and
(7) the expected battery life.’
It should be noted that the resistances of lead wires
and wire connections may be higher than the internal
resistance of the battery.
in the circuit (which consists of the internal battery resistance, rectifier dynamic resistance, current limiting
resistance, and impedance of power transformer). The
DC voltage of the circuit decreases with increasing
charge current due to the overall impedance. The V-I
performance of the charger depends on the circuit
resistance and the open the circuit voltage of the transformer. Figure 17 shows three different V-I performances by chargers P-, Q- and R-. The circuits of P
and Q have the same open circuit voltage, but their
impedances are different. The V-I relations of the battery a various states, from the discharged to the fully
charged condition are also illustrated.
1.7.5.3.(b) Unregulated Charger
This in one of the simplest chargers, and it is called a
transformer type charger. This type of charger consists of a power transformer, diodes, and a resistive element for limiting current. An elementary charging circuit is shown in Figure 16 from which the following basic electrical relations are derived.
These three chargers having different V-I characteristics, will provide different charging performances as
shown by solid lines in Figure 18.
Where Edc is an impressed voltage from a direct curr
ent power sourse, Eb is battery voltage during charge.
I is a charging current, and R is an overall impedance
The difference in V-I characteristics of the chargers results in different final steady state on charge voltages.
However, if these circuits are connected to the batteries through a voltage regulating device, charge performance curves will reach the same final state. This constant voltage charger will be discussed in the next section. The single phase charging circuits and design
equations are shown in figure 19.
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The symbols in Figure 19 are as follows:
Eac Open circuit rms source (secondary) voltage
Eb Battery voltage during overcharge
Ed Rectifier forward threshold voltage
IdcAverage overcharge current
R Total circuit resistance
K1 DC voltage equation factor (taken from Figure 20)
K2 DC current equation factor (taken from Figure 20)
K3 Current form factor (taken from Figure 20)
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6. Glossary of Terms
ACTIVE MATERIAL
The active electro-chemical materials used to manufacture positive and negative electrodes.
AMBIENT TEMPERATURE
The average temperature seen by the battery.
AMPERE – HOUR
The value obtained when the battery is normally used
to define capacity of the battery. It is the current in
amperes, multiplied by the time in hours, during which
current flows from the battery. Also expressed as milliampere-hours.
AVAILABLE CAPACITY
The capacity available from the battery based on its
state of charge, rate of discharge, and ambient temperature, to a specified cut-off voltage.
BATTERY
Two or more cells, connected together, normally in series. At times, a single cell may be referred to as a
battery.
C-RATE
A charge or discharge current rate, expressed in amperes or milliamperes. It is numerically the same as the
rated capacity of a battery expressed in ampere-hours.
CAPACITY
The electrical energy available from a cell or battery
expressed in ampere-hours. It refers to the discharge
of a constant current for a measure time to a specified
cut-off voltage (normally 1.75V /2V cell), at a specified
temperature.
CAPACITY FADE
Loss of capacity from inadequate recharging
CELL
The minimum unit of the battery that composes a storage battery, the nominal voltage of a cell of the Lead –
Acid Battery is 2.0V. Most batteries are made of 2 or
more cells. Typically 3 cells for a 6Volt, and 6 cells for
a 12Volt battery.
CELL REVERSAL
The polarity of cell voltage is inverted when the battery
is forced to discharge. Note that the service life of the
battery is shortened by the polarity inversion.
CHARGE
The process of restoring electrical energy to a cell or
battery.
CHARGE ACCEPTANCE
Expression of the degree to which the amount of electric
charge is effectively accumulated within the battery.
CHARGING EFFICIENCY
Expresses the degree of efficiency of accumulation of
charge electricity within the battery.
CHARGE RETENTION
Capacity is gradually lost during storage. Charge retention indicates the percentage of the capacity still remaining. Charge retention is also related to shelf life
and storage temperature.
CHARGE VOLTAGE
The value which is observed between the positive and
the nagative terminals while the battery is being charged.
CLOSED CIRCUIT VOLTAGE TEST
A test method in which the battery is briefly discharged
at a constant current, and the voltage is measured.
CONSTANT VOLTAGE CHARGE
One of the charge methods which has voltage limitation. When the discharged battery is charged by this
way, the charge current is reduced automatically according to the state of charge. This is the most recommendable charge method for SLA batteries.
CONSTANT CURRENT CHARGE
One of the charge methods which has current limitation. According to the charge time, some fixed amount
of capacity is charged. Therefore this charge method
requires some devices which prevent overcharge such
as timer etc., for SLA batteries.
CUT-OFF VOLTAGE
The final voltage of a cell or battery at the end of charge
or discharge.
CYCLE
A single charge and discharge of a cell or battery.
CYCLE LIFE
The number of cycles a cell or battery provides before
failure.
CYCLE USE
A method of using a secondary battery repeatedly by
charging and discharging.
DEEP DISCHARGE
The discharge of a cell or batter to 80 – 100% of its rated
capacity.
DEPTH OF DISCHARGE
Frequently expressed as a percentage, it is the amount
of capacity removed from a cell or battery during discharge.
DISCHARGE
The function of removing current from a cell or battery.
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71
DISCHARGE RATE
Normally expressed as a fraction of C : it is the rate at
which current is taken from a cell or battery.
DISCHARGE VOLTAGE
The closed circuit voltage of a battery during discharge.
DOT
The abbreviation for Department of Transportation (of
America).
DUTY CYCLE
The normal use of the battery in its application, includes
charge, discharge, and rest intervals.
END-OF-CHARGE VOLTAGE
The voltage reached by the cell or battery at the end –
of – charge, while the charger is still attached.
END-OF-DISCHARGE VOLTAGE
The final voltage of the cell or battery while the load is
still attached.
ELECTRODE
The positive or negative plate holding the active materials in the cell.
ELECTROLYTE
Conducts ions in the cell. Lead-Acid Batteries use sulfuric acid solution
ENERGY DENSITY
Ratio of cell or battery energy to weight or volume : watthours per pound or per cubic inch.
FAILURE MODE
The manner in which a cell fails to function. The typical
mode of failure for a Sealed Lead-Acid Battery is from
decomposition or sulphation of the plate over time, or
from dry-out of the electrolyte over time – due to use, or
to overcharge.
FLOAT
Maintains full capacity in a cell or battery by applying a
continuous charge. In this instance, the load is connected to the battery and current is provided from the
charger.
GAS ABSORPTION
The ability of the negative plate to absorb oxygen gas
generated within the battery ; the greater this ability,
the greater the current that can be used for charging.
HIGH-RATE DISCHARGE
A very rapid discharge of the battery : Normally in multiples of C.
IATA
The abbreviation for International Air Transport Association.
ICAO
The abbreviation for International Civil Aviation Organization.
INTERNAL IMPEDANCE
72 MICRO POWER
The resistive value of the battery to an A.C. current, expressed in ohms. Normally measured at 1,000Hz at full
charge.
INTERNAL PRESSURE
The pressure within a sealed battery ; oxygen is generated from the positive plate at the end of charging, causing internal pressure to increase.
INTERNAL RESISTANCE
The resistance within the battery ; an element that generates a voltage drop almost proportional to current.
INTERNAL SHORT CIRCUIT
Positive plates and negative plates touch together
through at the inside of the cell.
LIFE
The time period until the battery can no longer be used
because it has lost its characteristics. (See : Failure
Mode.)
LOW-VOLTAGE CUT-OFF
A sensor designed to end discharge at a predetermined
voltage level.
MAINTENANCE-FREE
Secondary cells that are not sealed require periodic
addition of water. Sealed Lead-Acid Batteries do not
require such maintenance. Therefore they are called
“maintenance free”
NOMINAL VOLTAGE
A nominal value to be used to indicate the battery voltage ; for the Sealed Lead – Acid Battery ; the nominal
voltage is 2V/cell.
NON-CONTROLLED CHARGE CURRENT
A charge current that can be maintained continuously,
regardless of the state of charge of the cell. Varies with
battery size.
OPEN-CIRCUIT VOLTAGE
The measured voltage of the cell or battery without a
load attached.
OVERCHARGE
The continuous charging of a cell after it achieves 100%
of capacity. The battery life is reduced by prolonged
over charge.
OVERCHARGE CURRENT
The charge current supplied during overcharge. Batteries can accept continuous overcharge at recommended rates and temperatures.
PARALLEL CHARGE
A charge method that charges multiple batteries at the
same time by the same charger at the same voltage.
Only in the case when ability of the charger is stable
enough, this method is available for trickle/float charge.
PRIMARY CELL
A cell that can be discharged only once. Example :
Manganese-zinc cells, Primary lithium cells
QUICK RECHARGEABILITY
The ability of quick charge acceptance of the batteries.
Quick recharge requires not only good charge acceptability but also safety devices such as thermostat, timers, etc.
RATED CAPACITY
The manufacture’s rated capacity of the cell. Panasonic
batteries are rated at C/20. (See : Capacity)
REFRESH CHARGE
A recovery charge which is done periodically for recovering the lost capacity of batteries due to self discharge.
RESEALABLE SAFETY VENT
The resealable safety device built into each cell of the
battery to release excess gas pressure and prevent
rupture.
SECONDARY BATTERY
A battery that can be charged and discharged repeatedly Example : Lead-Acid Batteries, Nickel-Cadmium
batteries.
SELF-DISCHARGE
The loss of capacity by a battery while in the stored or
unused condition. The rate of self-discharge is affected
by ambient temperature.
SEPARATOR
The material separating the electrodes. Used to hold
the electrolyte. Normally glass fiber is used.
SHELF LIFE
The life of a battery when stored in the unused condition. Panasonic batteries can be stored for extended
periods of time before use reuse (check handbook for
details)
SLA BATTERY
The SLA battery is a Sealed Lead-Acid Battery. It does
not need to have water added during its whole service
life. All Panasonic LCR, LCL, LCS, LCT and LCV batteries are SLA batteries. [See Maintenance-Free]
STAND-BY USE
A method of using secondary batteries in which the
battery is constantly charged so that it is always ready
for use.
STANDARD CHARGE
The normal charge rate used to charge a battery in 14
– 16 hours.
STATE-OF-CHARGE
Expressed as a percentage of C, it is the available capacity of a battery at a givin time.
TAB
Also called a lug. Used to connect batteries together
or as a terminal for connection to equipment.
THERMOSTAT
One of the safety parts of some models of the batteries.
It prevents swelling of the batteries when they are overcharged severely, and/ or cut off a rush current when
both terminals of the battery are accidentolly connected.
TRICKLE CHARGE
One of the back up methods used to operate the equipment in the case when AC power fails. While charging,
the batteries are not connected to the load. If AC power
fails, a relay connects the batteries to the load for backup purpose.
UL94 V-0
The flammable level of plastics listed on U.L. recognition. V-O means the most retarded grade of flammability of plastic resin. Panasonic LCV series batteries with
ABS resin meet this flammable level.
UL94 V-2
V-2 means the third retarded grade of flammability of
plastic resin.
Panasonic LCV series batteries with PP resin meet this
flammable level.
UNDERCHARGE
A charge state of the batteries caused by insufficient
charge.
UNDERVOLTAGE CUT-OFF
A sensor which cuts off discharge in order to prevent
cell reversal when the battery falls below preset cut off
voltage.
UPS
The abbreviation of Uninterruptible Power Supply
VdS
The abbreviation of Varband der Sachversicherer e.V.
Koln. One of battery standards in Germany.
VOLTAGE CUT-OFF
A sensor used to terminate a charge or discharge when
the battery voltage reaches a predetermined level.
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